Abstract
Hyperforin, a major active compound of St. Johnʼs wort extract, affects estrogenic
activity. In this study, the compound evoked estrogen response element-dependent luciferase
activity and cell proliferation in MCF-7 cells. Hyperforin-induced cell proliferation
was significantly inhibited by the estrogen receptor antagonist ICI 182,780. These
results suggested that hyperforin had estrogenic and cell proliferation activities,
which were stimulated via the estrogen receptor. Compared to 17β-estradiol, hyperforin showed significantly lower estrogenic activity and cell proliferation.
The mechanism underlying the estrogenic activity of hyperforin was unknown, therefore,
in this study, for the first time, the expression and post-translational modification
of proteins were determined and compared among control, 17β-estradiol-treated, and hyperforin-treated cells using proteomic techniques. A total
of 453 proteins were identified, of which 282 proteins were significantly modulated
in hyperforin-treated cells compared to 17β-estradiol-treated cells. Ingenuity pathway analysis also demonstrated that hyperforin
treatment induced less cell proliferation than 17β-estradiol by downregulating estrogen receptor 1. Protein network analysis showed
that cell proliferation was regulated mainly by cyclin D1 and extracellular signal-regulated
kinases. In conclusion, although, hyperforin exhibited lower estrogenic activity than
17β-estradiol, the compound induced lower levels of cancer cell proliferation in vitro.
Key words
Clusiaceae - estrogenic activity - hyperforin -
Hypericum perforatum
- Proteomics - St. Johnʼs wort